Zoo accreditation bodies set minimum standards for animal care, but wide variation exists between schemes, and accreditation alone does not guarantee high individual animal welfare.
Zoo accreditation provides an important baseline but should not be treated as a guarantee of welfare excellence. Accreditation schemes vary in the rigour of their welfare requirements and the frequency and thoroughness of inspections. A zoo that meets minimum accreditation standards may still house animals in environments that cause chronic stress, in social groups that are inappropriate, or with enrichment programmes that are inadequate for the species. The most meaningful welfare indicators go beyond accreditation to include time-activity budgets, stress hormone monitoring, and systematic behavioural observation of individual animals.